265/40R22 vs 305/30R24

305/30R24 is 0.86 in (21.8 mm) taller than 265/40R22, a +2.83% diameter difference. With the speedometer set for 265/40R22, an indicated 60 mph is 61.7 mph on 305/30R24.

Is this a safe swap?

Diameter difference +2.83%: within the ±3% guideline

By overall diameter alone, 305/30R24 falls inside the ±3% range commonly used as a guideline when replacing 265/40R22. This check uses diameter only. It does not assess load index, speed rating, wheel width or clearance.

Side profile and tread width, drawn to the same scale.

265/40R22 vs 305/30R24 differences
Measurement	265/40R22	305/30R24	Difference	% diff
Overall diameter	30.35 in (770.8 mm)	31.20 in (792.6 mm)	+0.86 in (+21.8 mm)	+2.83%
Sidewall height	4.17 in (106.0 mm)	3.60 in (91.5 mm)	−0.57 in (−14.5 mm)	−13.68%
Section width	10.43 in (265.0 mm)	12.01 in (305.0 mm)	+1.57 in (+40.0 mm)	+15.09%
Circumference	95.34 in (2,421.5 mm)	98.03 in (2,490.0 mm)	+2.70 in (+68.5 mm)	+2.83%
Revolutions per mile	665	646	−18	−2.75%

True speed with the speedometer calibrated for 265/40R22
Indicated	Actual on 265/40R22	Actual on 305/30R24	Difference
30 mph	30.0 mph	30.8 mph	+0.8 mph
60 mph	60.0 mph	61.7 mph	+1.7 mph
75 mph	75.0 mph	77.1 mph	+2.1 mph

Ride-height change: 305/30R24 raises the vehicle by 0.43 in (10.9 mm) at the axle (half the +21.8 mm diameter difference).

305/30R24 is 0.86 in taller than 265/40R22 and 40 mm wider, a 2.83% difference in overall diameter.

With the speedometer calibrated for 265/40R22, an indicated 60 mph is actually 61.7 mph on 305/30R24, and revolutions per mile change from 665 to 646.

305/30R24 mounts on a 24-inch wheel, a plus-2 fitment from the 22-inch wheel of 265/40R22.

Size pages

Other comparisons with 265/40R22

Other comparisons with 305/30R24

Source: Calculated from standard tire geometry formulas. Verified 2026-09-27. How these numbers are calculated.